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Feb. 3, 1931. F. HHAGUE t 1,791,025

STEERING GEAR, MORE ESPECIALLY TO STEERING GEAR FOR MOTOR ROAD VEHICLES Feb. A3, 1931. F. H. HAGUE 1,791,025

STEERING GEAR, MORE ESPECIALLY To STEERING GEAR FOR MOTOR ROAD VEHICLB Filed May 6, 1929 2 Sheets-.Sheet 2 FRA/wf Hawnen Maz/5 INVENTOR Minnie Patented Feb. 3, 1931 ernten STATES igerozs FRANK HOWARD'HAGUE, OE LONDON, ENGLAND STEERING GEAR, MORE ESPECIALLY To STEERING GEAREOR MOTOR ROAD VEHICLES Appiication :ned may e, i929, serial No. 360,802, and in Great Driiamiiiay 14, ieae.

The present invention relates to steering gear. More especially it rela-testo steering gear for motor road vehicles, wherein a man* ually operated steering wheel orrthe like is l employed and some form of reduction gear provided between the said wheel and the road -wheels, rsuch that the angular` movement of theroad wheels is less than the angular movef ment of the steering wheels. The invention i will be described forr convenience'with reference to motor road vehicles only but Vit `will be readily understood from the description that it may be employed for steering other vehicles such for example as motor boats.

According to theinvention the steering.

wheel is integral with or operatively connected with an element such as a. disc or plate, or` cam (hereinafter referred to as the steering wheel cam) which moves angularly in its own plane on movement of the steering wheel. The said steering wheel camy is formed or provided with a track, such for example as a groove or slot which'or a part or parts of which lies or lie in a direction having both radial and circumferential comi ponente in relation to the axis of rotation of the said cam, such for example as a spirally curved or scroll-like track, Mounted in association with the steering wheel cam and parallel therewith o are two other elements such as plates or discs one of which is fixed (hereinafter termedv the fixed disc) and ther other of which (hereinafter termed thek steeringV shaft disc) is rotatable about the 3.5 geometrical axis of movement of the steering wheel cam and rigidly connected with-the? steering column shaft or like'element throughl which the actuation of the steering road wheels is effected.V The fixed vdisc and the steering shaft disc are each provided. with a Y track such for example as a slot or groove lyn ing in directions having both radial and circumferential components in relation to the common geometrical axis of movement of the steering wheel cam. and lthe steering shaft disc and reversely inclined Vor intersecting `when superposed, or the track inV one of the said discs may lie in a direction as indicated and the other in a radial direction. There is also provided acoinmon member slidaloly-V tracksjare preferably so designed and iiiterrelated that the action is irreversible, that is to say motion can betransmitted to the steer# ing wheel shaft by rotation of the steering wheel but not from the steering shaft toy the steering wheel. v y n In 'order that the invention `may be more fully understood and .re'adilycarriedl intok effect it lwill now bendescribed with reference to the accompanying drawings which illus-`l `trate,oneconstructional form thereof. YIn

these drawings, f Y v Figure 1 is an axial section through the steeringrgear and Figure 2 isa face view with one outer disc removed, on the lines 2-2 of Figure l. In the-form of the invention shown there'is rigidly mounted any convenient manner at the top of a hollowsteering column l and concentric therewith a laterally disposed cylindrical box comprising two circular plates 2, 2 spaced apart by a cylindrical i ring 3, and connected by suitable Yfastening' PATENTE.; voi-rica i f means such for example as bolts and nuts 4t.

These two plates 2, 2 are each provided vwith a curved slot 5, 5Y extending from a point near thecentre to a pointnear the periphery and `lying generally in afdireetion ,having both radial and circumferential components,

that is to say in a direction inclined to any radius traversing the slot. The slot 5 of the plate 2 is exactly opposite to the slot 5 ofthe other plate 2 andthe two platesfwith their slots constitute .the fixed disc hereinbefere.re-` ferred to. The disposition of the said slats Vis clearly shown in Figure` 2 where lthere is indicated in dotted lines the slot 5 of tlie plate 2', the other plate 2 being assumed in `*Figure 2 to have been removed. Within the cylindrical box `referred to mounted another cylindrical box-like arrangement coin-' prising a circular plate 6 -rigidly mounted other circular plate 6 with an aiinularilaiige vao 8 spaced from the first mentioned plate 6 and connected therewith by castellations 9 upon the edge Aof the annular flange 8 coacting with notches formed in the edge of the plate tl attached to the steering'v shaft v7. These two plates 6 and 6 so connected constitute the steering shaft disc above referred to andl they are provided withslots 10, 10 imi-V lar-to the slots 5, 5 justdescribed as being provided iii the plates 2 and2, but reversely inclined, or in other. words so inclinedl that they intersect with the first mentioned slot 5, 5 when superposed. The slot 10 in the plate 6 and its disposition appear clearly in Figure 2 and it will be understood that the other slot lOlics exactly behind the Aslot 10. lithiii the second mentioned cylindrical boi: constituted by the plates 6, 6 and the flange there, is disposed another disc 11 which is integral with a spindle 12 extending upwards throughsuitable orifices iii the plates and 2 above it and to the top of which spindletlie manually operable steering wheel is attached. This central cylindrical plate 11 is provided with a spiral or scroll-lille slot 12'extending from a point near the centre to a' point near the periphery and occupying an angular eX- tent of about y360 degrees.A This centralplate' 11 constitutes the steering Wheel cam above referred to. ExtendingY through the said spiral or scrolland also through the slots 5,

10, 10', 5 of all the circular plates referred to is a pin 13 provided with coned rollers 11i" which are a working lit within the said spiral' or scroll 12 and the various slots.

Thus on rotation of the steering wheel the pin with its rollers will be moved inra direction following that of the slots in the fixed: disc, that is to say the slots in the plates 2 and 2, and owing to the fact that it also engages in the slots in the steering shaft disc that is to say in the plates 6 'and 6 the latter will be rotated in relation to the former as the point of intersection of the two slots is altered by i movement of the pin through the action of the cam slot or scroll l2. The general arrangement of the scroll and slots as shown is such f it will be that a complete revolution of the steering wheel in clockwise direction as seen in Figure 2 results in an angular movement of the steering shaft disc from the point A to the point B, that isto say through about 90 degrees.

The scroll may be so plotted that about midway of its angular. extent corresponding with the straight steering position a relatively large movement of thesteering wheel effects a relatively small movement of the steering sha-ft while onk either side of this central position the curvature of the scroll may be so varied that the ratio of angular movement of the steering wheel to angular movement of vshaft disc would be reduced. slow slope to the spiral or scroll 12'how y ever gives the irreversible feature and a dei the steering shaft is progressively decreased.

The several plates of the construction dey up by removing shims or thin washers from the clearance 15 and tightening up the bolts Vand nuts 4. Thin cover plates l1o are also provided to complete Hthe assembly and to cover the open sides of the slots in the outer plates'2 and 2Q In the foregoing description of the construction illustratedin the drawings it has been stated that the box-like assembly comprising the plates 2, 2 etc., is mounted rigidly upon the upper end of a hollow steering lcolumn. This part of the assembly may however be fixed in any other convenient manner; thus for example by means of suitable lugsfor'y brackets it'might be attached to the dash board or scuttle of a motor vehicle orfit could be placed at the lower end of the steering column or in'any other convenient position Aaxially aligned with the steering column andi shaft. n

Suitable lightening holes or recesses may of course' be provided in any or all ofthe various plates constituting the gear.v

As mentioned above, with the cam `spiral on sloped more steeply to the axis becliosen,l the" angular movement of tliesteering wheel cani for given angular movement of theY steering A; relatively Asirable reduction gearing between the' steering wheel cam and the steering shaft disc. To Ysecure the selfloclring feature itvwill be seen that for any position ofthe partsfor example theposition indicated by Figure 2; the angle betweenthe tangent to the slots 5 and 5 ofthe iixed'disc7 at the position of the pin and rollers 13, lil, and theliiorinal'to the tangent to the wallofthe cam spiral'or scroll 12 at thev pointV of contact with the said pin and rollers, must be less than the angle of friction of the science of mechanics., Generally speaking to secure the irreversible feature `the various slots are so chosen that the direction of pressurefand re-y action, as determined by the slots 5, 5', betweenthe pin and rollers "and the wall of the cam spiral or scrolls'lot is approximately ynormalto the tangent to the curve Voi rae said spiral or scroll at the point of ContactV Different:relationships between the angular movement'offthe steering wheel cam andthe ing different curves for the spiral'or scrollor the slots-'5, 5', 10, 10', or both, andiinA one steering shaft discmay be obtained by select-l r. ne

at different relative angular positions of theV steering wheel cam and the steering shaft disc. The curves necessary to secure the relationships desired may be obtained readily by geometrical plotting methods.v

I claim Y l l. Steering gear comprising twodisc-like elements co-axially mounted, tracks in the said elements which 'intersect at different points in their length and atv different radial distances from the common axis with variation of the angular relation of the said disclike elements, a member slidably and simultaneously engaging both said tracks atvtheir intersection, and operating means for varying the radial distance of the said member rom the common axis to cause relative rotation between the two disc-like elements to effect the steering operation. Y i

2. Steering gear comprising a fixed disc and a steering shaft disc'mounted co-axially, tracks in the fixed disc and steering shaft disc which intersect at different points in their length and at different radial distances from the common axis with variation of the angular relation of the said fixed disc and steering shaft disc, a member slidably andV simultaneously engaging both said tracks, and operatingv means rotatable about .the common axis for varying the radial distance of the said member from the common axis to cause rotation of the steering shaft disc relatively to the xed disc. y

3. Steering gear comprising a steering wheel cam provided with a track lying in a direction having both radialand circumferential components, a fixed disc and a steering shaft disc mounted co-axially therewith, tracks in the fixed disc and steering shaft disc which intersect at different points in their length and at dierent radial distances from the common axis with variation of the angular relation of the said fixed disc and steering e shaft disc and which alsointersect the track in the -steering wheel cam, and a member slidably and simultaneously engaging allthree tracks at their intersection wherebyy on rotation of the steering wheel camV` the radial distance of the" said member from the common axis is varied to cause rotation of the steering shaft disc relatively to the fixed disc.V Y

4. Steering gear comprising two' disc-like elements co-axially mounted, each said element having a track lying in a direction hav-V ing both radial and circumferential components the two said tracks intersecting when superposed, a member slidably and simultaneously engaging both said' tracks atthe'ir intersection, and operating means for varying the radial distance of the said member from the common axis to cause relative rotaeffect the steering-operation.

5. Steering gear comprising two disc-like ously engaging all the slots, p described. tion between the two disc-like elements to elements co-axially mounted,v tracks in the said elements which intersect at ydifferent points in their length and at different radial distances from the common axis with variationof the angular relation of the said elements, a member slidably and simultaneously engaging both said tracks at their intersection and operating means rotatable about the conmion axis and having a spiralgroove engaging the said member whereby on rotating.v the operating. means in one direction or thel lother the said member is moved radially in one direction or the other to vary the distance l of the point of intersection of the tracks in the said disc-like elements andso produce relative rotation of the said elements to effect the steering operation, the said spiral track being adaptedY to act as a stop fory the said n track engaging element precluding movement.

y force apthereof in either radial direction plied thereto.

6. Steering gear comprising a steering.

wheel cam provided with a spiral' slot therein, v

av fixed disc and a 'steering shaft disc mounted co-axiallyvwith and adjacent to the said steering wheel cam, reversely inclined curved slots in the said discs each having both radial and circumferential components, and a member extending throughout and simultaneously and slidably engaging all three said slots at their intersection, the sum of the angular eX- tents of the slots in the two said discs being substantially smaller than the angular extent of the spiral slot in the steering wheel cam to providea reduction ratio between the rotation of the steering wheel cam and the rotation of the steering shaft disc relatively to the fixed disc.

7 Steering gear comprising Ya steering wheel cam in disc form provided with ya spiral slot therein, two discs mountedco-axially one on each -side of the said steering wheel caml and rotatable in relation thereto, thetwo said discs being connected at their peripheries beyond the periphery of the steering wheel cam,

one connected rigidly with a steering shaft and each provided with a curved slot having both radial and circumferential components, the said slots coeinciding as viewed in the axial direction, two discs mounted co-axially one on each side of the aforesaid assembly, connected together at their peripheries beyond the periphery of the said assembly, held fixed against rotation, and each provided with l a curved slot havingvboth radial and circumferential components, the said slots co-inciding as viewed in the axial direction but being reversed in inclination as compared. with the slots lin the discs in next inside relation Ato them, and a member slidably and simultanesubstantially as FRANK HOWARD HAGUE. 

